Film-winding control and counter for roll-holding cameras



April. 10, 1951 D. c. HARVEY 2,548,530

FILM-WINDING CONTROL AND COUNTER FOR ROLL-HOLDING CAMERAS Filed April16, 1948 2 Sheets-Sheet 1 -FIG.1.

FIG. 2.

DOUGLAS S C. HARVEY N VlEN TOR I WM/ BY M A 'ITORNEYS April 10, 1951 c,HARVEY 2,548,530

FILM-WINDING CONTROL AND COUNTER FOR ROLL-HOLDING CAMERAS Filed April16, 1948 2 Sheets-Sheet 2 DOUGLASS c. HARVEY IN VEN TOR ATTORNEYSPatented Apr. 10, 1951 FILM-WINDING CONTROL AND COUNTER FOR ROLL-HOLDING CAMERAS Douglass C. Harvey, Rochester, N. Y., assignor to EastmanKodak Company, Rochester, N. Y., a corporation of New Jersey ApplicationApril 16, 1948, Serial No. 21,388"

Claims.

This invention relates to photography and particularly to a roll filmwinding control and exposure counter for =roll-holding cameras. Oneobject of my invention is to provide a film-winding control which willrelieve the operator'of the necessity of watching for numerals on thebacking paper at a red window in winding film. Another object of myinvention is to provide a relatively simple mechanism having but fewparts arranged in such a manner that there is but little likelihood ofthe apparatus being mishandled. Another object of my invention is toprovide a simple type of film-winding and counting mechanism'which canbe'reset and moved to various positions without danger of injuring themechanism. A still further object of my invention is to provide a simpletype of film-measuring device and release which can readily be appliedto roll-holding cameras with a minimum change in the parts thereof.Other objects will appear from the following specification, the novelfeatures being particularly pointed out in the claims at the endthereof.

This mechanism may be considered as an improvement over the-mechanismshown in a copending application in the names of D. C. Harvey and E. S.Marvin, Ser. No. 774,804 filed September 18, 1947, now Patent No.2,544,879 of March 13, 1951, for Film Metering Double ExposurePrevention Camera. The mechanism has been simplified in the presentapplicationand certain disadvantages of the film-winding control shownin the copending application have been overcome in the presentmechanism.

Coming now to the'drawings wherein like reference characters denote likeparts throughout:

Fig. 1 is a side elevation of a typical camera having a film-windingcontrol and counter constructed in accordance with and embodying apreferred form of my'in-vention;

Fig. 2 is an enlarged plan view of the counter dial removed from thecamera;

Fig. 3 is a side elevation of the film-winding control mechanism showingthe relationship of the mechanism parts after a film area has been woundinto an exposure position and when the camera is ready to make a secondexposure;

Fig. 4 is an enlarged end elevation showing a portion of the windingmechanism shown in Fig. 3, certain parts being omitted;

Fig. 5 is a view similar to Fig. 3 but with the parts in the startingposition just after the film backing paper has been threaded to thespool and before the first film area is positioned for anexposure; V l

2. Fig. 6 is an enlarged fragmentary detail showing a portion of themeasuring ratchet and measuring pawl inc-position for winding thebacking paper and before a film area is positioned for exposure; P 4

,Fig. 7 is a rear elevation of the camera shown in'Fig. 1; j

Fig. 8 is a schematic showing of the film path and exposure frame usedin the camera shown in Figs. 1 and-7. V

In order to illustrate a preferred embodiment of my invention Ihaveshown my-improved form of film-winding and counting control forcameras asbeing applied to atwin-lens' reflex type of camera. Asindicated in Fig.1,the camera 1; is of a known type employing anobjective in a mount'2 for taking pictures and a second objective in amount 3 for forming an image of the picture to be taken on a groundglass which is covered by a hood 4 shown in a closed position in Fig. 1.A shutter 5 supports the lens cell 2 and a trigger Bis used to releasethe shutter. The side wall 7 of the camera carries the usual type offilm-winding knob 8 and is provided with a window 9 through whichnumbers In on a counting disk I- can be successively viewed {as they arebrought beneath the window 9. -A re-;-

lease handle-l2 extends-through a 'slot in the sidewall 1, this releasebeing used to; move fth'e stop pawl, to be later described, to aninoperative position after each exposure. It is obvious that myimprovedwindingcontrol mechanism may be applied to other types ofcameras and it isto be understood that this particular form of theinvention is merely an illustration of a preferred application of myinvention.

- Myimproved film-winding and counting con-, trol for cameras consistsof a counter pawl and a stop pawl cooperating with the counter ratchetand a stop ratchet in such a manner that a film operator, in moving fromone film to the next, manually releases the stop-pawl after eachexposure and then merely winds the film until the stop pawl halts thewinding movement so that it is unnecessary to use the window in thecamera back to determine successive-exposures, although i this window isnecessary in initially loading and positioning the first film area inplace. As indicated-in Figs. 3 and 5, a shaft I I2, whic carries awinding knob 8, as indicated in Fig. 1, also carries a stop ratchet [3.This ratchet is keyed to the shaft H2 and is designedt'o stop themovement of thisshaft after a predetermined rotation thereof inpositioning a film for exposure. A stop pawl 14 is used for this pur.

pose; this pawl consisting of several parts. The stop pawl may turn upona shaft i on which shaft a slide i5 is also mounted for limited movementradially of the shaft through an elongated opening H. A lug IS on theslide is connected to a lug IS on the pawl l4 by means of a spring 20 sothat the slide is always held toward the pivot I5. The slide is alsoprovided with an elongated opening 2|) which may slide about anupstanding pin 2| terminating on the outside of thecamera with the knobl2 and constituting a means for releasin the stop pawl M. The stop pawlmay be provided with a single stop ratchet engaging point 22, or it mayhave, a second stop ratchet engaging pawl member 23 pivoted to the pawlM at 24. The pawl M includesv a lug M connected by a spring,25 to.astud26. The second pawl 23, if used, will include a lug 21 connected bya spring 28 to the stud 26. Thus, the point of each pawl isnormallymoved toward the stop ratchet l3. A pin 29 on the second pawl 23,through its engagement with the surface 3!! of pawl M, will bemoved fromthe stop ratchet l3 when the knob I2 is raised to release the stopratchet.

If a single pawl point 22 is used, the apparatus will worksatisfactorily, but there is one difiiculty and, that is, that thespacing between the exposure areas may not be the same since it willmake a difference in the spacing whether the pawl initially lies at thebase of a ratchet tooth, as shown in Fig. 3, or whether it lies near thetop of a ratchet tooth. If more even spacing is required, the secondpawl 23 may be applied which reduces the error at least by half. Anothersolution would be to make smaller ratchet teeth on the stop ratchet I3,but this is inadvisable because finer teeth are more difficult to makeand a greater strain is placed on the fine teeth by the stop pawl.

The pawl I4 is provided with a downwardly extending lug 3| which lug isof a width less than thewidth W of a notch 32 in a notched disk 33.Thus, the lug 3| is normally drawn into a notch 32 by the spring 25. Thelug 3| may, however, be held from a notch 32 by means of a lug 34extending downwardlyfrom the slide I6. This lug is of the same length,or longer, than lug 3| and may project below lug 3|. The lug 34 on theslide l6 and the lug 3| on the stop pawl L4 may be made to telescope, oroverlap, as in Fig. 3, in which position both lugs may pass into a notch32. However, if the knob I2 is raised, as in Fig. 3, releasing the pawlpoints 22 and 23 from the stop ratchet l3, the spring 20 will move theslide l6 radially toward the pivot |5 so that instead of overlapping, asin Fi 3, the lug 34 will move relative to the lug 3| so that the totalwidth of the two lugs will be greater than the width W of a notch in thenotched disk. Consequently, the pawl l4 will be held out of a notch whenit is raised because the lug 34 will rest on the periphery 35 of thenotched disk between two of the notches 32. If lug 34 projects below lug3|, it may more readily engage and be moved by a notch 32.

If the winding knob 8 is now turned, the periphery 35 will move past thetwo lugs until the next succeeding notch 32 strikes the lug 34,- therebymoving the slide'away from its expanded position'withrespect to lug 3|and causing the lugs tov again telescope to a totalwidthof less thananotch 32-, so that when the lug 3| rides oif the periphery 35, bothlugs. willbe drawndown into anotch 32, as-illustratedin Fig. 3.

The notched disk 33 is mounted on a shaft 37, this shaft having a flat38 by which the notched disk and a measuring ratchet 39 are movedtogether and to which the measuring or counting disk is attached to movewith both the notched disk 33 and the measuring ratchet 39. Thismeasuring ratchet has a plurality of teeth 40 around its periphery,although at one area, as indicated in Fig. 6, there is a mutilatedportion 4| where several teeth are removed. In order to move themeasuring ratchet 39, there is a measuring pawl 42 having a pawl point43 engaging the teeth and being driven by an eccentric pin 44 carried bya roller 45 over which a film F passes, as .shownin the diagram in Fig.8. The pawl 42 has a clearance aperture 48 for the stud 2B-and mayoscillate freely about the stud without contacting with it. A lug 4'! onthe measuring pawl. is connected by a spring 48 to one arm 49 of a bellcrank lever-50 pivotally mounted on aestuditandheldby the sprin so thattwo ratchet teeth 52 and 53, spaced-apart a distance, so that when onetooth engages -a measuringpawl tooth, the other tooth engages midwaybetween two ratchet teeth; This bell crank lever merely preventsbackward movement ofv the measuring ratchet39. The pawl 42, drivenby theeccentric 44; makes a number of shortstrokes each.time the film roller45 revolves. Thus 44 constitutes a crank having a. measuring pawlto,-.,operat.e mechanism when the-film. is wound. A. numbetr of thesesmall impulses of thecrank turn the notched disk a plurality of stepsinbetween each notch 32 and, while I have shown the scale of themeasuring. ratchet somewhat enlarged, I prefer to have'at least five.revolutions of the film wheel 35 while a film area is movedpast anexposure frame 55-shown in Fig.8. By having a large number of smallimpulses .on the measuring ratchet 42, it is possible for extremelylight pressure between the film F and the film roller 45to drive themeasuring and counting. mechanism very readily. This is particularlytrue where the roller 15 is provided with finev points fifiwhich maysink into the emulsion layer on afilm to secure better traction.

In some instances-gears have been used to con-. nect a driving rollerover which film passes to a measuring roll or notched disk, but onedifiiculty with such av mechanism is that a slip clutch has to beprovided. in order to set the mechanism for its initial exposure and ifthe slip mechanism does not. work smoothly, the mechanism may be bent ordamaged in endeavoring to set it. These difficulties are. overcomewithmy improved form of mechanism because the stop disk and measuringratchet may alwaysbe turned in a counter-clockwise direction when thehandle I2 is moved to lift the stop pawls from the stop ratchet.

The operation of loading. and. exposing. a film in a camera equippedwiththe above-described measuring mechanism is exceedingly simple. Thecamera back 6| may be opened for loading the film into the positionshown in they diagram in Fig. 8 in the usual manner. The leader strip orbacking paper may be-attached to atake-up hub 5? of a film spool 58being drawn out from a supply spool 59. The film backing paper 13 isattached to a film by a paster P in theusual manner andafter attachingthe backing paper to the take-up spool 58; the'handle |2 maybe raisedand the knob 63 on the measuring. disk may be turned to the zeroposition, as shown in Fig. 2. In this position, as illustrated-'in'Fig.5;

the notched disk is arranged with a wide projection I 35 beneath thelugs 3! and 34 which are separated a width greater than the width W of anotch 32 because the holding pawl I4 is raised and the spring mayseparate these lugs. If, now, the handle I 2 is released, the parts willrest on the wide periphery section I and, at the same time, themutilated portion M, as illustrated in Fig. 5, will 'be brought oppositethe measuring pawl @3. Therefore, as an operator turns the winding knob8, the pawl 43 will idle back and forth in the mutilated portion ll ofthe measuring ratchet and will continue to do so until the operatorturns a handle I0 on the camera back moving a shutter from a red windowH so that he can see the approach of the numeral 1 indicating the firstfilm is in position for exposure. When 1 appears in thered window II,the operator then merely moves the knob 60 until the numeral 1 appearsbeneath the window 9. In doing this, the measuring ratchet 39 is movedso that the pawl 43 may engage a tooth, the lug 34 is engaged by a notch32 and partially telescoping over lug 3I whereupon the holding pawl 22or 23 may engage a tooth of the holding ratchet 53 so that the film islocked against movement and the camera is ready for an exposure.

After making an exposure, handle I2 is raised, permitting the slide I6to move lug 34 relative to lug 3| to a total width greater than thewidth W of a notch, thereby immediately holding the pawl I4 away fromthe stop ratchet I3 until film is wound. Winding film causes the pawl 42to move a plurality of strokes, each stroke advancing the measuringratchet 39 one tooth and until the next successive notch 32 reaches,first, the lug 34, sliding it radially of the pawl I4 and, second, thelug 3|, at which time both lugs will drop into the notch immediatelyhalting the winding movement by one or the other of the pawls 22- or 23.The camera is again ready for exposure.

It will be noted that the mechanism is simple. Most of the parts aremade from stamped metal and are consequently inexpensive and there isbut little mechanism which can be damaged. If the operator should try toturn the knob 80 with the pawl I4 in an operative position, this cannotbe done since the notched disk 33 is definitely locked. However, byraising the handle I2 and unlocking the notched disk 33, the operatormay turn the disk 33 if he turns in a counter-clockwise direction.Clockwise movement is prohibited by the bell crank lever 53. If theoperator should forget to set the mechanism and has taken a number ofexposures, say three, he can,

by looking at the number on the film, set the counting disk I I at anytime by raising the handle I2 and turning the knob until the propernumeral appears in the window 9. Applicant believes that this mechanismis as near foolproof as any mechanism for automatically controlling andcounting winding can very well be, and yet it is extremely simple tooperate and reliable in use. It is not necessary to provide the pawl I4with two separately moving pawl points 22 and 23 unless extremely evenspacing is required between exposures. However, the structure with theadditional pawl point 23 can be added so readily and at so little extraexpense that it is a preferred construction. It is understood that theviews (except those in 1, 7, and 8) are on a very much enlarged scale tobetter illustrate the invention and that consequently the parts whichappear quite large in the drawingsare actually confined to acomparatively small space.

1 claim: .1. Film winding control for cameras of the type having acamera body, an exposure frame therein, a film spool support, a'filmwinding knob for moving film across the exposure frame by turning a filmspool held by the support, a roller to be turned by film moved by thewinding knob each time a fresh exposure area of film passes thereover,said control comprising a stop ratchet movable with the winding knob, astop pawl carried by the camera body, a crank carried by the rollerhaving a measuring pawl thereon, a measuring ratchet and notched diskpivotally mounted on the camera body and movable together when themeasuring pawl engages and moves the measuring ratchet, a lug carried bythe stop pawl of less width than a notch of the notched disk and adaptedto drop therein, a slide mounted on the stop pawl and having a lu ofless width than a notch of the notched disk, spring means for holdingthe two lugs adjacent each other with a total width greater than a notchin the notched disk whereby said lugs may engage the outer periphery ofthe notched disk, said slide being movable against the spring means tooverlap the two lugs when an edge of a notch in the notched disk engagesand moves one lug relative to the other, permitting the lugs on the stoppawl and slide to drop into a notch in the notched disk andsimultaneously permitting the stop pawl to drop into'the stop ratchetafter the notched disk is driven by a film to measure 01f an exposurelength of film.

2. Film winding control for cameras as defined in claim 1 characterizedin that there is a manually operable means for moving the stop pawl fromthe stop ratchet a distance to allow the sprin means to move-the slidelug longitudinally of the stop pawl lug to span a notch in the notcheddisk.

3. Film winding control for cameras as defined in claim 1 characterizedin that the slide lug is longer than the stop pawl lug to projectbeneath said lug whereby said slide lug may start to engage a notch inthe notched disk as the latter is moved enabling the notched disk to'move the slide until the stop pawl lug may also engage a notch of thenotched disk.

4. Film winding control for cameras as defined in claim 1 characterizedin that there is a manually operable means for movin the stop pawl fromthe stop ratchet a distance to allow the spring means to move the slidelug longitudinally of the stop pawl lug to span a notch in the notcheddisk, said notched disk and measuring ratchet being mounted to turn witha shaft carrying a dial plate toturn therewith, graduations on the dialplate to indicate the numbers of exposures and a film-threadingposition, the measuring ratchet having a mutilated portion positionableopposite the measuring pawl to render the latterinoperative when thedial plate is turned to the film-threading position.

5. Film winding control for cameras a defined V in claim 1 characterizedin that there is a manually Operable means for moving the stop pawl fromthe stop ratchet a distance to allow the spring means to move the slidelug longitudinally of the stop pawl lug to, span a notch in the notcheddisk, said notched disk and measuring ratchet being mounted to turn witha shaft carrying a dial'plate to turn therewith, graduations on the dialplate to indicate the numbers of exposures :and a film-threadingposition, the

measuring ratchet havin a mutilated portion positionable opposite themeasuring paw1-to render the latter inoperative when the dial plate isturned to the film-threading position, and the notched di'sk includingan elongated peripheral space between notches in the notched disk, saidelongatedspace'being positioned under the slide lug and stop pawl lugwhen the dial plate is manually set to a starting position.

DOUGLASS C. HARVEY.

REFEEENCES CITED The following-references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

